ResponseIncludeWrapper.java 文件源码

/**
 * Return a OutputStream, throws and exception if a printwriter already
 * been returned.
 * 
 * @return a OutputStream object
 * @exception java.io.IOException
 *                if the printwriter already been called
 */
@Override
public ServletOutputStream getOutputStream() throws java.io.IOException {
    if (printWriter == null) {
        if (servletOutputStream == null) {
            servletOutputStream = captureServletOutputStream;
        }
        return servletOutputStream;
    }
    throw new IllegalStateException();
}